Make List.join about 20% faster
Make List.join about 20% faster

- presize memory and bind string values rather than pushing
- tighten str copy loop

salortiz/rakudo,nbrown/rakudo,b2gills/rakudo,raydiak/rakudo,lucasbuchala/rakudo,rakudo/rakudo,jonathanstowe/rakudo,azawawi/rakudo,MasterDuke17/rakudo,usev6/rakudo,Gnouc/rakudo,azawawi/rakudo,awwaiid/rakudo,azawawi/rakudo,awwaiid/rakudo,MasterDuke17/rakudo,samcv/rakudo,Gnouc/rakudo,zostay/rakudo,softmoth/rakudo,tony-o/rakudo,ab5tract/rakudo,b2gills/rakudo,tbrowder/rakudo,lucasbuchala/rakudo,raydiak/rakudo,tony-o/rakudo,rakudo/rakudo,b2gills/rakudo,sjn/rakudo,awwaiid/rakudo,ab5tract/rakudo,labster/rakudo,tony-o/rakudo,b2gills/rakudo,zostay/rakudo,ab5tract/rakudo,jonathanstowe/rakudo,sjn/rakudo,sjn/rakudo,Gnouc/rakudo,nbrown/rakudo,sjn/rakudo,ab5tract/rakudo,jonathanstowe/rakudo,tony-o/rakudo,nbrown/rakudo,salortiz/rakudo,salortiz/rakudo,rakudo/rakudo,labster/rakudo,lucasbuchala/rakudo,nbrown/rakudo,azawawi/rakudo,samcv/rakudo,usev6/rakudo,tbrowder/rakudo,usev6/rakudo,softmoth/rakudo,MasterDuke17/rakudo,salortiz/rakudo,tony-o/rakudo,usev6/rakudo,labster/rakudo,MasterDuke17/rakudo,ab5tract/rakudo,labster/rakudo,samcv/rakudo,sjn/rakudo,zostay/rakudo,rakudo/rakudo,tbrowder/rakudo,lucasbuchala/rakudo,softmoth/rakudo,labster/rakudo,nbrown/rakudo,awwaiid/rakudo,Gnouc/rakudo,salortiz/rakudo,raydiak/rakudo,softmoth/rakudo,lucasbuchala/rakudo,rakudo/rakudo,b2gills/rakudo,MasterDuke17/rakudo,Gnouc/rakudo,raydiak/rakudo,tbrowder/rakudo,labster/rakudo,softmoth/rakudo,tony-o/rakudo,jonathanstowe/rakudo,salortiz/rakudo,Gnouc/rakudo,tbrowder/rakudo,zostay/rakudo,usev6/rakudo,MasterDuke17/rakudo,samcv/rakudo,jonathanstowe/rakudo,rakudo/rakudo,tbrowder/rakudo,samcv/rakudo,awwaiid/rakudo,azawawi/rakudo,nbrown/rakudo